1. Field of the Invention
The invention is directed to an improved armature and method for producing an armature including a shaft and at least five sheet metal laminations fixed on the shaft.
2. Description of the Prior Art
It is known to affix a lamination bundle, which is comprised of a number of sheet metal laminations, to a rotor shaft by means of pressing them onto the shaft in order to produce an armature for an electric machine. There is both positive and frictional engagement between each sheet metal lamination and the rotor shaft. Particularly with a large number of sheet metal laminations, i.e. a long lamination bundle, it is difficult to fasten this to the rotor shaft in one step without damaging sheet metal laminations and/or the rotor shaft. Frequently, so-called stepped rotor shafts are used, which are complex to produce and are more expensive.
It is also known to fasten a lamination bundle to a rotor shaft by attaching only a beginning region and an end region, which are each comprised of at least one sheet metal lamination, to the rotor shaft by means of caulking. Particularly with long lamination bundles and high torques, there is the possibility of the sheet metal laminations between the beginning region and the end region shifting due to insufficient holding forces in the lamination bundle.